Imagerie PI2

@article{,

title = {Psoralen crosslinking between human immunodeficiency virus type 1 RNA and primer tRNA3(Lys)},

author = {E Skripkin and C Isel and R Marquet and B Ehresmann and C Ehresmann},

url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=8602365},

isbn = {8602365},

year  = {1996},

date = {1996-01-01},

journal = {Nucleic Acids Res},

volume = {24},

number = {3},

pages = {509-514},

abstract = {Initiation of reverse transcription is a crucial step of retroviral infection. In HIV-1, it involves hybridization of the 18 3'-terminal nucleotides of the primer tRNA3(Lys) to the primer binding site (PBS) of the viral RNA. Moreover, additional interactions between the two RNAs were recently evidenced [Isel et al. (1995) J. Mol. Biol. 247, 25269-25272]. To get further information on the topology of the viral RNA/tRNA3(Lys) complex, we used psoralen to induce RNA-RNA crosslinking. A defined intermolecular crosslinked complex was obtained. The crosslinked regions were characterized by RNase T1 digestion followed by bi-dimensional gel electrophoresis. The crosslinked residues (nucleotide mcm5S2U34 and U35 in the anticodon loop of tRNA3(Lys) and UCU154 in the viral RNA upstream of the PBS) were mapped using a retardation method coupled with random hydrolysis. The formation of this crosslink depends on the same elements that are required for the formation of the extended interactions between primer and template RNAs, i.e., the modified bases of the tRNA and a conserved A-rich loop located upstream of the PBS in the genomic RNA. Therefore, the present crosslinking data provide relevant information on the topology of the template/primer binary complex.},

note = {0305-1048 

Journal Article},

keywords = {Base Sequence  Cross-Linking Reagents/*metabolism  Ficusin/*metabolism  HIV-1/*genetics  Human  Molecular Sequence Data  Molecular Structure  RNA, Lys/*genetics/metabolism  RNA, MARQUET, Non-U.S. Gov't, Transfer, Unité ARN, Viral/*genetics/metabolism  Support},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Initiation of reverse transcription of HIV-1: secondary structure of the HIV-1 RNA/tRNA(3Lys) (template/primer)},

author = {C Isel and C Ehresmann and G Keith and B Ehresmann and R Marquet},

url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=7707372},

isbn = {7707372},

year  = {1995},

date = {1995-01-01},

journal = {J Mol Biol},

volume = {247},

number = {2},

pages = {236-250},

abstract = {Reverse transcription of human immunodeficiency virus type-1 (HIV-1) genomic RNA is primed by tRNA(3Lys), whose 3' end 18 nucleotides are complementary to the viral primer binding site (PBS). We used chemical and enzymatic probes to test the conformation of the viral RNA and tRNA(3Lys), in their free form and in the HIV-1 RNA/tRNA(3Lys) binary complex. Extensive reactivity changes were observed in both molecules upon formation of the binary complex. In the viral RNA, reactivity changes occurred up to 69 nucleotides upstream and 72 nucleotides downstream of the PBS. A secondary structure model of the HIV-1 RNA/tRNA(3Lys) complex accounting for all probing data has been constructed. It reveals an unexpectedly complex and compact pseudoknot-like structure in which most of the anticodon loop, the 3' strand of the anticodon stem and the 5' part of the variable loop of tRNA(3Lys) interact with viral sequences 12 to 39 nucleotides upstream of the PBS. The core of the binary complex is a complex junction formed by two single-stranded sequences of tRNA(3Lys), an intramolecular viral helix, an intramolecular tRNA helix, and two intermolecular helices formed by the template/primer interaction. This junction probably highly constrains the tertiary structure of the HIV-1 RNA/tRNA(3Lys) complex. Compared to the structure of the free molecules, only the D arm of tRNA(3Lys) and a small viral stem-loop downstream of the PBS are unaffected in the binary complex. Sequence comparison reveals that the main characteristics of the binary complex model are conserved among all HIV-1 isolates.},

note = {0022-2836 

Journal Article},

keywords = {Base Sequence  Binding Sites  Conserved Sequence  HIV-1/*genetics  Models, Genetic, Lys/*genetics/metabolism  RNA, MARQUET, Molecular  Molecular Probes  Molecular Sequence Data  *Nucleic Acid Conformation  RNA, Non-U.S. Gov't  *Transcription, Transfer, Unité ARN, Viral/*genetics/metabolism  Structure-Activity Relationship  Support},

pubstate = {published},

tppubtype = {article}

}